Wondering how can you activate your Borderlands 2 Season Pass on Steam?

A lot of people are experiencing errors that doesn't let them open the season pass or use it. A common error message experienced:This item requires you own the base game "Borderlands 2 RU" before it can be added to your library

To solve this, contact STEAM Support and mention your problem.

It DOES work. The wait period (as of this time) is around 3 or so days.